src/core/service.h

/* SPDX-License-Identifier: LGPL-2.1+ */
#pragma once

typedef struct Service Service;
typedef struct ServiceFDStore ServiceFDStore;

#include "exit-status.h"
#include "kill.h"
#include "path.h"
#include "ratelimit.h"
#include "socket.h"
#include "unit.h"

typedef enum ServiceRestart {
        SERVICE_RESTART_NO,
        SERVICE_RESTART_ON_SUCCESS,
        SERVICE_RESTART_ON_FAILURE,
        SERVICE_RESTART_ON_ABNORMAL,
        SERVICE_RESTART_ON_WATCHDOG,
        SERVICE_RESTART_ON_ABORT,
        SERVICE_RESTART_ALWAYS,
        _SERVICE_RESTART_MAX,
        _SERVICE_RESTART_INVALID = -1
} ServiceRestart;

typedef enum ServiceType {
        SERVICE_SIMPLE,   /* we fork and go on right-away (i.e. modern socket activated daemons) */
        SERVICE_FORKING,  /* forks by itself (i.e. traditional daemons) */
        SERVICE_ONESHOT,  /* we fork and wait until the program finishes (i.e. programs like fsck which run and need to finish before we continue) */
        SERVICE_DBUS,     /* we fork and wait until a specific D-Bus name appears on the bus */
        SERVICE_NOTIFY,   /* we fork and wait until a daemon sends us a ready message with sd_notify() */
        SERVICE_IDLE,     /* much like simple, but delay exec() until all jobs are dispatched. */
        SERVICE_EXEC,     /* we fork and wait until we execute exec() (this means our own setup is waited for) */
        _SERVICE_TYPE_MAX,
        _SERVICE_TYPE_INVALID = -1
} ServiceType;

typedef enum ServiceExecCommand {
        SERVICE_EXEC_START_PRE,
        SERVICE_EXEC_START,
        SERVICE_EXEC_START_POST,
        SERVICE_EXEC_RELOAD,
        SERVICE_EXEC_STOP,
        SERVICE_EXEC_STOP_POST,
        _SERVICE_EXEC_COMMAND_MAX,
        _SERVICE_EXEC_COMMAND_INVALID = -1
} ServiceExecCommand;

typedef enum NotifyState {
        NOTIFY_UNKNOWN,
        NOTIFY_READY,
        NOTIFY_RELOADING,
        NOTIFY_STOPPING,
        _NOTIFY_STATE_MAX,
        _NOTIFY_STATE_INVALID = -1
} NotifyState;

/* The values of this enum are referenced in man/systemd.exec.xml and src/shared/bus-unit-util.c.
 * Update those sources for each change to this enum. */
typedef enum ServiceResult {
        SERVICE_SUCCESS,
        SERVICE_FAILURE_RESOURCES, /* a bit of a misnomer, just our catch-all error for errnos we didn't expect */
        SERVICE_FAILURE_PROTOCOL,
        SERVICE_FAILURE_TIMEOUT,
        SERVICE_FAILURE_EXIT_CODE,
        SERVICE_FAILURE_SIGNAL,
        SERVICE_FAILURE_CORE_DUMP,
        SERVICE_FAILURE_WATCHDOG,
        SERVICE_FAILURE_START_LIMIT_HIT,
        _SERVICE_RESULT_MAX,
        _SERVICE_RESULT_INVALID = -1
} ServiceResult;

struct ServiceFDStore {
        Service *service;

        int fd;
        char *fdname;
        sd_event_source *event_source;

        LIST_FIELDS(ServiceFDStore, fd_store);
};

struct Service {
        Unit meta;

        ServiceType type;
        ServiceRestart restart;
        ExitStatusSet restart_prevent_status;
        ExitStatusSet restart_force_status;
        ExitStatusSet success_status;

        /* If set we'll read the main daemon PID from this file */
        char *pid_file;

        usec_t restart_usec;
        usec_t timeout_start_usec;
        usec_t timeout_stop_usec;
        usec_t runtime_max_usec;

        dual_timestamp watchdog_timestamp;
        usec_t watchdog_usec;            /* the requested watchdog timeout in the unit file */
        usec_t watchdog_original_usec;   /* the watchdog timeout that was in effect when the unit was started, i.e. the timeout the forked off processes currently see */
        usec_t watchdog_override_usec;   /* the watchdog timeout requested by the service itself through sd_notify() */
        bool watchdog_override_enable;
        sd_event_source *watchdog_event_source;

        ExecCommand* exec_command[_SERVICE_EXEC_COMMAND_MAX];

        ExecContext exec_context;
        KillContext kill_context;
        CGroupContext cgroup_context;

        ServiceState state, deserialized_state;

        /* The exit status of the real main process */
        ExecStatus main_exec_status;

        /* The currently executed control process */
        ExecCommand *control_command;

        /* The currently executed main process, which may be NULL if
         * the main process got started via forking mode and not by
         * us */
        ExecCommand *main_command;

        /* The ID of the control command currently being executed */
        ServiceExecCommand control_command_id;

        /* Runtime data of the execution context */
        ExecRuntime *exec_runtime;
        DynamicCreds dynamic_creds;

        pid_t main_pid, control_pid;
        int socket_fd;
        SocketPeer *peer;
        bool socket_fd_selinux_context_net;

        bool permissions_start_only;
        bool root_directory_start_only;
        bool remain_after_exit;
        bool guess_main_pid;

        /* If we shut down, remember why */
        ServiceResult result;
        ServiceResult reload_result;

        bool main_pid_known:1;
        bool main_pid_alien:1;
        bool bus_name_good:1;
        bool forbid_restart:1;
        /* Keep restart intention between UNIT_FAILED and UNIT_ACTIVATING */
        bool will_auto_restart:1;
        bool start_timeout_defined:1;

        char *bus_name;
        char *bus_name_owner; /* unique name of the current owner */

        char *status_text;
        int status_errno;

        UnitRef accept_socket;

        sd_event_source *timer_event_source;
        PathSpec *pid_file_pathspec;

        NotifyAccess notify_access;
        NotifyState notify_state;

        sd_event_source *exec_fd_event_source;

        ServiceFDStore *fd_store;
        size_t n_fd_store;
        unsigned n_fd_store_max;
        unsigned n_keep_fd_store;

        char *usb_function_descriptors;
        char *usb_function_strings;

        int stdin_fd;
        int stdout_fd;
        int stderr_fd;

        unsigned n_restarts;
        bool flush_n_restarts;
        bool exec_fd_hot;
};

extern const UnitVTable service_vtable;

int service_set_socket_fd(Service *s, int fd, struct Socket *socket, bool selinux_context_net);
void service_close_socket_fd(Service *s);

const char* service_restart_to_string(ServiceRestart i) _const_;
ServiceRestart service_restart_from_string(const char *s) _pure_;

const char* service_type_to_string(ServiceType i) _const_;
ServiceType service_type_from_string(const char *s) _pure_;

const char* service_exec_command_to_string(ServiceExecCommand i) _const_;
ServiceExecCommand service_exec_command_from_string(const char *s) _pure_;

const char* notify_state_to_string(NotifyState i) _const_;
NotifyState notify_state_from_string(const char *s) _pure_;

const char* service_result_to_string(ServiceResult i) _const_;
ServiceResult service_result_from_string(const char *s) _pure_;

DEFINE_CAST(SERVICE, Service);

#define STATUS_TEXT_MAX (16U*1024U)